Drip on nettle (4)
I believe the answer is:
weed
I believe this is a double definition.
'drip' is the first definition.
(thesaurus)
'nettle' is the second definition.
(thesaurus)
'on' is the link.
(Other definitions for weed that I've seen before include "Unwanted plant - cannabis" , "Intrusive plant; weak person" , "Went" , "gardening" , "dope" .)